Men Need Better Understanding of PCa Genetic Test Results

Some men who undergo multigene testing for inherited prostate cancer misinterpret findings of variants of uncertain significance.

CHICAGO—Understanding of personal genetic test results is lacking in some men who undergo multigene testing for inherited prostate cancer (PCa), according to study findings presented at the American Society of Clinical Oncology (ASCO) Annual Meeting.1

The findings are from a study of 109 men who completed surveys before and after they underwent genetic testing (GT). The pre-GT survey included 15 items that assessed knowledge of cancer risk and genetics (KCRG) and 6 items that assess health literacy and numeracy. The post-GT survey included 9 items that assessed understanding GT results. The investigators, led by Veda N. Giri, MD, a medical oncologist at the Sidney Kimmel Cancer Center at Thomas Jefferson University in Philadelphia, also categorized personal and family history into 3 hereditary cancer syndromes (HCS) linked to PCa.

“Having a strong family history of cancer was associated with higher cancer knowledge and knowledge of cancer genetics, which might be expected if there was perhaps conversation about inherited cancer risk in a family,” said Dr Giri, an Associate Professor in the Department of Medical Oncology and Director of Cancer Risk Assessment and Clinical Cancer Genetics at Thomas Jefferson University.

Factors significantly associated with higher pre-GT KCRG included meeting HCS criteria and higher numeracy. On multivariable analysis, family history of meeting criteria for an HCS remained significantly predictive of higher KCRG. Of 101 men who responded definitively regarding understanding of personal GT results, 13 responded incorrectly on mutation status. Twelve of these men had 1 or more variants of uncertain significance (VUS), but reported that their test results showed a mutation.

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That a subgroup of men did not understand their test results is concerning, Dr Giri said, because these men might pass misinformation to their providers and family members. Though many of these VUS are not in known PCa genes, they are in genes that have other cancer risks that could be acted upon inappropriately, leading to unwarranted screening and risk reduction interventions if men incorrectly think they have a mutation. Further study will be needed to confirm these findings. Dedicated efforts are needed to help men better understand VUS findings uncovered from multigene testing for PCa, she said.